net: graceful exit from netif_alloc_netdev_queues()

User space can crash kernel with

ip link add ifb10 numtxqueues 100000 type ifb

We must replace a BUG_ON() by proper test and return -EINVAL for
crazy values.

Fixes: b68aa76a0b296 ("net: allow large number of tx queues")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index 6778a9999d525307d5bd41a1750a6e96a6e22bf3..0ad6262143328f2a0bd6546a772703be9dab17bf 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6409,7 +6409,8 @@ static int netif_alloc_netdev_queues(struct net_device *dev)
        struct netdev_queue *tx;
        size_t sz = count * sizeof(*tx);
 
-       BUG_ON(count < 1 || count > 0xffff);
+       if (count < 1 || count > 0xffff)
+               return -EINVAL;
 
        tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
        if (!tx) {